Duplicating machine plate clamp



Feb. 19, 1952 H. F. BRuNs DUPLICATING MACHINE PLATE CLAMP Filed March 31, 1949 3 Sheets-Sheet 1 Feb. 19, 1952 H. F, BRUNS DUPLICATING MACHINE PLATE CLAMP 3 Sheets-Sheet 2 Filed March 5l, 1949 SWW/Mo@ Hs fer Ffunj.

ATTOR N EYS Feb. 19, 1952 H. F. BRUNs 2,586,146

DUPLICATING MACHINE PLATE CLAMP Filed March 5l, 1949 3 Sheets-Sheet 3 me/wm Eerber .577025 ATTOR N EYS Patented Feb. 19, 19-52 DUPLICATING *AMACHINE PLATE CLAMP Herbert F. Bruns, Chicago, Ill., assignor, by mesne assignments, to Ditto, Incorporated, Chicago, Ill., a corporation of West Virginia Appiioation March 31, 1949,-Seria1 No. 84,509 13 ciaims. (o1. 1in-415.1)

The present application is a continuation-inpart of the prior application of Harold R. Gullixson and Herbert F. Bruns, Serial No. 712,538, led November 27, 1946, and covers divisible subl ject matter which is the sole invention of the present applicant, although originally disclosed in said joint application.

The invention relates to a sheet or plate clamp-4 ing mechanism,.particularly adapted for use in association with the plate-holding segment Vof a duplicating machine cylinder. The invention is not confined to such use, however, as it may readily be employed with other types of machines.

The primary object of the invention is to provide clamps for the leading and trailing edges of a master sheet or plate, which effectively grip and hold the same, against any possibility of displacement in use, yet which may be quickly and easily opened and closed, for the insertion and re moval of the sheets or plates.

Another object of the invention is to provide a clamping mechanism in which the jaws are maintained closed, in gripping relation to the sheet, by spring action. Y Y

Another object is to previde a clamp for one end of a master sheet or plate which is so mount;V

ed that tension is applied to the sheet, to maintain the same rmly in engagement with the adjacent surface oi' the cylinder.

Still another object of the invention is to provide a clamp in which the jaws are maintained closed and in which the clamp as a whole is urged in a direction to tension the sheet on the cylinder, by common spring means.

Another object of the invention is to provide improved means for opening the jaws of aplate or sheet clamp, against the action of spring means tending to close the same.

Another object is to provide, in a plate or sheet clamp, means for indenting the plate or sheet, without rupturing the same, to perform the dual functions of preventing slippage of the plate relative to the clamp and of indexing the .position of the plate in the clamp, so that it may be reinserted therein, at a subsequent time, in exactly the same position, or in a slightly changed position, as desired. g

Other and further objects and advantages; of the invention will be apparent from a consideration of the specific embodiments ofthe invenftion, shown for purposes of illustration in the accompanying drawings, in which:

Figure 1 is a radial section through one form.

of head clamp and a fragmentary portion of a duplicating machine cylinder;

Figure 2 is a similar View of one form of tailclamp;

Figure 3 is a View similar' to Figure 2, showing the clamp in the open position;

Figure 4 is a horizontal section on line 4-'4 of Figure 2;

Figure 5 is an axial section on line 5 5 of Figure 2;

Figure 6 is an elevation on line 6 6 of Figure 2;

Figure 7v is a section on line 'I--l of Figure 6, showing the outer jaw and handle mechanism only;

Figure 8 is a similar section on line 8-8 of Figure 6;

Figure 9 is a plan view of a modied form of inner clamping plate or strip;

Figure 10 is a section similar to Figure l, showing the modification of Figure 9;

Figure l1 is a sectional view of another form of clamping strip or plate;

Figure l2 is a sectional view of a modied form of head clamp, and

Figure 13 is a similar, sectional view of a tail clamp embodying the principles of the modication shown in Figure 12.

SinceV the invention is not limited to any-particular type of printing or duplicating machine, a complete machine is not shown herein, but reference is made to theabove-identied joint application for a disclosure of a typical apparatus with which the clamps lmay be employed. Referring to Figures 1 and 2, the plate holding segment Iii oi a duplicating machine cylinder is provided at the leading end II, with a radially inwardly extending flange I2 and, at the trailing end I3 with a similar flange Iii. The cyiinder may be of the type shown in the above mentioned application, in' which two segments are provided, one to hold the master plate or sheet, having the image to be reproduced disposed thereon, and the other to receive the paper sheets, to which the image is applied by the blanket roll; or the cylinder may be ofthe type employed in twocylinder machines, .in which one cylinder carries theV master plate or sheet and the other carries the paper to be printed. In either oase, the surface of the cylinder is interrupted, and the clamping means are secured to the circumferential end faces, in the space provided by the interruption.

As shown in Figure l., an elongated, axially ertending jaw plate l5 is provided with a plurality of radial slots IS, slidably embracing enlarged necks I1 formed on screws I3 having heads it on their outer ends, the screws being received in tapped bores in the ange I2. The jaw plate l5 at its upper end is turned laterally to provide a head 28 and a jaw element 2i, having downwardly and inwardly `:facing jaw edge 22 above a channel 23. Y

Surrounding the shank of each screw It is an apertured Aspacer block 25, upon which the plate I5 may slide in a radial plane. inwardly of the a secure blocks 25 is a leaf 28 of a hinge 21, the leaf being appropriately apertured for the reception of the screws I8. The hinge 21 may be of the piano type and may include a pin 28 and one or more leaves 29 pivotally mounted thereon and provided with downturned ends 39, seated upon the radially inner surface of the channel 23, with the inclined portion of the leaf or leaves disposed below the jaw edge 22.

The plate I carries, at its ends, apertured lugs 3l, to which are connected the outer ends of tension springs 32, secu-red at their inner ends to appropriate pins or hooks carried by the heads or spokes of the cylinder. Reference character 33 in Figure 1 represents a handle mechanism, explained in detail in connection with the tail clamp shown in Figures 2-8.

The leaf 29 constitutes a clamping strip or plate, having a pivotal connection at its opposite ends with the jaw plate and with the supporting means for the jaw plate, respectively. When the jaw plate is moved radially outwardly, against tension of springs 32, as indicated in dotted lines in Figure 1, the jaw element 2| iecedes from the clamping plate 29.

The tail clamp comprises a similarjaw plate a, which may be identical to the plate associated with the head clamp, but simply turned around to face in the opposite direction. The plate and associated parts, in this instance, however, are mounted for swinging movement away from the end face of the flange I4 at the trailing end of the plate holding segment. An elongated hinge 35 of the piano type has an upwardly Aextending leaf 36 secured to the end face of the flange I4 by countersunk screws 31. To the second leaf 38 of the hinge 35 there is attached a downwardly extending leaf 39 of a second hinge 40, by means of a plurality of bolts 4I, extending through registering apertures in spacer blocks 42. Nuts 43 having reduced necks disposed in the slots I6a in jaw plate .15a hold the parts together. Lock nuts 44 may be employed, if desired.

The second leaf 45 of the second hinge 48 has a downturned end 4E. disposed within the channel 23a of the jaw plate, as previously explained.

Preferably, the second hinge is sectional or is constituted by a plurality (e. g. four) of independent hinges, as indicated in Figures 4 and 5. Springs 32a, connected to lugs 3Ia, as previously explained, tend to move the jaw plate radially inwardly to the closed position. In addition,v

these springs, being laterally offset from an axial plane passing through the pivot pin of hinge 35, tend to swing .the clamping mechanism as a whole in a clockwise direction, to the open position of the first hinge as shown in Figure 3. The swinging movement in this direction is limited by clips 50, secured to the end faces of the cylinder and having inwardly turned ends 5I lying behind the jaw plate I5a.

One end 52 of a handle lever 53 is pivoted upon the shank of one of the nuts 43. The lever carries an inwardly projecting roller 54, lying below the lower edge of the jaw plate I5a. Between the point where the roller 54 is attached and the opposite end 55, the lever is bent outwardly as at 55, so that the latter end portion clears the adjacent screw 4I and the nuts 43 and 44 mounted thereon, as indicated in Figures 4 and 6. The last-mentioned screw 4I carries the upper end 51 of a bracket 58, having its outer or rear end 59 turned upwardly, to provide a channel or pocket for receiving the lever, for

limiting its downward movement, and for guiding the same in its swinging movements. The end 55 of thelever preferably has a laterally turned finger piece 60, by which the lever may be swung upwardly, about its other end as a fulcrum, to lift the jaw plate and to swing the hinge 35 from the open position, as indicated in Figure 3, toward the cylinder, against the tension of springs 32a, to facilitate the introduction of the trailing end P' of the master plate or sheet P. When the handle or lever is released, the springs 32a. move the jaw plate inwardly to grip the master plate. Thereafter they tend to swing the jaws in a clockwise direction to apply tension to the strip or sheet on the surface of the cylinder.

It has been found desirable, particularly in the use of certain types of master plates or sheets, to provide means for indenting the plates and for tightly gripping the same at a plurality of spaced points along their leading and/or trailing edges. As shown in Figures 9 and 10, this desirable result may be accomplished by providing in the clamping strip or hinge 65, a plurality of pairs of apertures, through which wire loops 85 may be threaded, with their inner ends 51 turned up against the undersurface thereof, to secure the wires in place. The wire loops provide protuberances upon the surface of the clamping plate or strip, in closely spaced relation to the edge 22D of the jaw plate I5b. With a jaw opening proportioned as shown in Figure 10, the downturned edge of the leaf at 30 and 46 as shown in Figures 1, 2 and 3 may be eliminated, and a simple, planar leaf 65 employed.

As shown in Figure 11, the protuberances 10 may be provided, by striking upwardly, spaced portions of the metal of which the leaf cr plate 1I is made.

In the form of the invention shown in Figures l2 and 13, the hinge is arranged somewhat differently, since the hinge pin is spaced from the adjacent end of the plate holding segment of the cylinder, and the free edge of the hinge projects toward, instead of away from the cylinder. Referring to the head clamp shown in Figure 12, an elongated strip or bar 18 is secured to the flange I2 of the cylinder, by any appropriate means. A plurality of spacer blocks 19 are clamped against the outer face of the strip 18, by means of bolts having enlarged necks 82 and heads 8|. Slidably mounted on the necks 82 are a pair of plates 83, 84, secured to each other by rivets or the like, and having vertically elongated slots 85, embracing the necks 82. The outer plate 83 constitutes a jaw element and is provided at its upper edge with a laterally turned flange 81 providing a downwardly facing jaw edge. The inner plate 84 constitutes one element of a hinge, including a pin 88 and a second leaf 89. The free edge of the latter projects rearwardly and is seated upon the upper edge of the strip or bar 18. A spring 98 connected to the plates 83 and 84 urges the latter downwardly to the closed position as shown in full lines in Figure 12. A handle 9I may be mounted as previously described, to facilitate opening of the jaw. Springs 92, connected to the blocks 19 and the leaf 89 maintain the free edge of the latter upon the strip 18. When the plates 83 and 84 are raised to the dotted line position, the leaf 85 pivots on the upper edge of the strip 18, and the jaws are opened. Protuberances 66', similar to those described in connection with Figure 10 may be associated with the leaf 89.

The tail clamp shown in Figure 13 embodies the same principle as the head-clamp shown inV Figure l2; Parts bearing prime numbers may be-identical with those shown in Figure 12 and described above. The strip or bar 18', however, has its inner surface recessed as at 95, to accommodate the head 96 of av bolt 91, upon the outer end of which a nut 98 having a neck 99 is threaded, the nut being retained in place by a lock nut I-llil. Interposed between the outer face of the strip 'i8' and theblocks I9 lis one leaf llll of a hinge, including a pin |62, and a second leaf H33,- the latter being extended upwardly into the space 95 and being secured to the flange i4 of the cylinder by countersunk screws |04. It will be readily appreciated that the entire jaw assembly may be swung rearwardly, away from the flange |4- of theplate holding segment ofthe cylinder, under the influence of the spring 99' and that, when a plate or master sheet is clamped between the jaws, the tendency of the spring will be to close the jaws and apply tension to the sheet;

In the clamps shown in Figures l2 and 13, outward movement ofthe interconnected plates 83, 84, and 83', -84' causes the jaws 81 and 81 to recede from the clamping strips 89 and 89' as the latter pivot along their inner and outer edges, on the associated hinge pins and on the upper surface of the bars or plates 'IB and 18'. The

hinge pins 88 and 88 are each disposed below the associated laterally projecting jaw plate while the free edge of each clamping strip or plate rests upon a surface xed with respect to the cylinder, instead of upon a surface associated with the jaw plate; Otherwise, the action is quite similar to the embodiment shown in Figures 2-8 and 10.

The invention is not limited to the details of construction shown in the accompanying drawings and described above, but includes all modifications coming `within the scope of the appended claims and their equivalents.

I claim: l

l. A clamp for securing a master sheet upon the surface of a cylinder in a duplicating machine or the like, comprising an elongated plate having a laterally facing jaw, a plate support, means for mounting the plate on the support for sliding movement in its own plane in a direction transverse to its length, a clamping strip having one edge underlying said jaw and pivotally supported at that edge for movement with respect to the plate as the jaw is moved-and having its other edge pivotally supported on an axis xed with respect to the `plate support, whereby the jaw recedes from -the strip when moved in one direction and approaches the same in clamping relation when moved in the other direction, and means for urging the plate in the last mentioned direction.

2. A clamp for securing a master sheet upon the surface of the sheet carrying segment of a duplicating machine cylinder or the like, comprising an elongated plate extending axially of said cylinder substantially in a radial plane thereof, means for supporting the plate for limited, substantially radial, sliding movement, a jaw carried by the plate, turned laterally and having a free edge projecting toward the adjacent surface of the cylinder, a clamping strip supported by the cylinder at one edge for pivoting movement with respect thereto and supported at its opposite edge by the plate below the jaw for pivoting movement with respect thereto, whereby the strip recedes from the jaw when the plate is moved radially outwardly and approachesV the jaw when the plate is moved radially inward- 1y, and means maintaining the plate in the last mentioned position.

3. A clamp for securing a master sheet upon the surface of the sheet carrying segment of a duplicating machine cylinder or the like, comprising an elongated plate extending axially of Said cylinder substantially in a radial plane thereof,- means for supporting the plate for limited, substantially radial, sliding movement, ajaw carried by the plate, turned laterally and having a free edge projecting toward the adjacent surface of the cylinder, a clamping strip supported by the cylinder at one edge for pivoting movement with respect thereto, projecting away from the cylinder toward the jaw and supported at its opposite edge by the plate below the jaw for pivoting movement with respect thereto, whereby the strip recedes from the jaw when the plate is moved radially outwardly and approaches the jaw when the plate is moved radially inwardly and resilient means urging the plate inwardly.

4. A clamp for securing a master sheet upon the surface of the sheet carrying segment of a vduplicating machine cylinder or the like, comprising a member carried by said cylinder adjacent an end of said segment and restrained against radial movement with respect thereto, an elongated jaw member extending axially of the cylinder having a laterally facing undercut jaw element projecting toward the adjacent end of the segment, said jaw member being connected to the first-mentioned member for limited substantially radial movement relative thereto, a

.; clamping strip pvotally supported at one edge by the first-mentioned member, projecting away from the adjacent end of the segment and supported at the other edge by the jaw member and underlying said surface, whereby, when the jaw member is projected outwardly, said surface recedes from the strip and, when moved inwardly, approaches said strip in clamping relation, and means for maintaining the jaw member in the inwardly moved position.

5. A clamp for securing a master sheet upon the surface of the sheet carrying segment of a duplicating machine cylinder or the like, comprising a member carried by said cylinder adjacent an end of said segment and restrained against radial movement with respect thereto, an elongated jaw member extending axially of the cylinder having a laterally facing undercut jaw element projecting toward the adjacent end of the segment, said jaw member being connected to the first-mentioned member for limited substantially radial movement relative thereto, and a clamping strip underlying the jaw element and hingedly connected to one of said members with its opposite edge disposed upon the other member for pivoting movement with respect thereto, whereby, when the jaw member is projected outwardly, said jaw element recedes from the strip and, when moved inwardly, approaches said strip cylinder havingia` laterally facing undercut jaw elementprojectingtoward the adjacent end of the segment, `said -jaw'lmember being connected to the first-mentioned member for limited sub-1 stantially radial movement relative thereto, a hinge having one leaf connected to one of said members and another leaf extending laterally toward the other member and supported thereby for pivoting movement with respect thereto, the last-mentioned leaf having a portion underlying the jaw element, whereby, when the jaw member is moved outwardly, said jaw element recedes from the last-mentioned leaf and approaches the same when moved inwardly, and means for urging the jaw member inwardly.

7. A clamp for securing a master sheet upon the surface of thesheet carrying segment of a duplicating machine cylinder or the like, comprising a member carried by said cylinder adjacent an end of said segment and restrained against radial movement with respect thereto, an elongated jaw member extending axially of the cylinder having a laterally facing undercut jaw element projecting toward the adjacent end of the segment, said jaw member being connected to the first-mentioned member for limited substantially radialmovement relative thereto, an elongated hinge having one leaf connected to the first-mentioned member and another leaf projecting laterally therefrom, below said jaw element with its free end pivotally supported upon the jaw member, whereby, when the jaw member is projected outwardly, said element recedes from the strip and, when moved inwardly, approaches said strip in clamping relation, and means for maintaining the jaw member in the inwardly moved position.

8. A `clamp for securing a master sheet upon the surface of the sheet carrying segment of a duplicating machine cylinder or the like, comprising a member carried by said cylinder adjacent an end of said segment and restrained against radial movement with respect thereto, an elongated jaw member extending axially of the cylinder having a laterally facing undercut jaw element projecting toward the adjacent end of the segment, said jaw member being connected L to the first-mentioned member for limited substantially radial movement relative thereto, an elongated hinge having one leaf secured to the jaw member below said jaw element and the other leaf projecting laterally toward the firstl tending outwardly from the connection with the rst leaf, a sheet clamping jaw plate supported by the second leaf for limited radial movement with respect thereto, said plate having a laterally anddownwardly facing jaw surface, and a second jaw plate underlying said surface, pivotally connected at one edge to a part xed with respect to the second leaf and at the other edge to said jaw plate, whereby outward radial movement of the rst jaw plate causes the jaw surface to recede from the second jaw plate and inward movement thereof brings the same together, and

spring means for urging the rst jaw plate inwardly and for swinging the second leaf away from said end of the cylinder to clamp a master sheet in the jaws and to tension the same upon the'surface of the cylinder.

10. A clamp for securing a master sheet upon the surface of an interrupted cylinder of a duplicating machine or the like, comprising an axially extending hinge having one leaf secured to a circumferential end portion of the cylinder adjacent the interruption therein and a second leaf extending outwardly from the connection with the first leaf, a sheet clamping jaw plate-having a laterally projecting jaw supported by the second leaf for limited radial movement with respect thereto, a third hinge leaf operatively connected to the second hinge leaf and underlying the jaw and constituting a second jaw element, whereby outward movement of the plate causes the jaws to separate and inward movement thereof causes the jaws to close, and means for urging the plate and rst jaw inwardly and for swinging the second leaf away from said end of the cylinder to tension a master sheet on said surface.

11. A clamp for securing a master sheet upon the surface of an interrupted cylinder in a duplicating machine or the like, comprising an elongated, axially extending plate disposed substantially on a radial plane of the cylinder inwardly of the surface thereof within the interrupted portion, means for supporting the plate for limited substantially radial, sliding movement, ajaw carried by the plate projecting laterally toward the adjacent surface of the cylinder, restrained against inward, radial, sliding movement, a clamping surface supported by the cylinder and underlying the jaw, spring means for urging the jaw inwardly to clamp an inserted sheet upon said surface and means for moving the jaw outwardly against the Aforce of said spring means, the last-mentioned means comprising a lever pivoted to a part fixed with respect to the cylinder for movement in a substantially radial plane, connected to the plate and having a free end arranged for manual manipulation.

12. A clamp for securing a master sheet upon the surface of an interrupted cylinder in a duplicating machine or the like, comprising an elongated, axially extending plate disposed substantially on a radial plane of the cylinder inwardly of the surface thereof within the interrupted portion, means for supporting the plate for limited substantially radial, sliding movement, a jaw carried by the plate projecting laterally toward the adjacent surface of the cylinder, a clamping surface supported by the cylinder restrained against inward, radial, sliding movement and underlying the jaw, spring means for urging the jaw inwardly to clamp an inserted sheet upon said surface and a lever for moving the plate and jaw outwardly against the force of the spring means, said lever being pivotally connected to the plate supporting means for movement in a substantially radial plane, having a portion underlying and engaging the plate and having a free end arranged for manual manipulation.

' 13. A clamp for securing a master sheet upon the surface of an interrupted cylinder in a duplicating machine or the like, comprising an elonif gated, axially extending plate disposed substantially on a radial plane of the cylinder inwardly of the surface thereof within the interrupted portion, means for supporting the plate for limited substantially radial, sliding movement, a jaw carried by the plate projecting laterally toward the adjacent surface of the cylinder, a clamping surface supported by the cylinder restrained against inward, radial sliding movement and underlying the jaw, spring means for urging the jaw inwardly to clamp an inserted sheet upon said surface, and a lever for moving the plate and jaw outwardly against the force of the lastmentioned means, said lever being pivoted at one end to the plate supporting means for movement in a substantially radial plane, having an intermediate part underlying the plate and having its other end shaped to facilitate outward swinging movement thereof.

HERBERT F. BRUNS.

l REFERENCES CITED The following references are of record in the file of this patent:

Number UNITED STATES PATENTS Neal Sept. 22, 1942 

